Vegetation Types Research Articles

Associations of vegetable and potato intakes with markers of type 2 diabetes risk in the AusDiab cohort.

The associations of vegetable and potato intakes with type 2 diabetes (T2D) appear to be nuanced, depending on vegetable types and preparation method, respectively. We investigated the associations of total vegetable, vegetable subgroup, and potato intakes with 1) markers of T2D at baseline and 2) incident T2D cumulative over a 12-year follow-up period in Australian adults. Using data from the Australian Diabetes, Obesity and Lifestyle Study, intakes of vegetables and potatoes were assessed via a food frequency questionnaire at baseline. Associations between vegetable intake and 1) fasting plasma glucose (FPG), 2-hour post load plasma glucose (PLG), updated homeostasis model assessment of β-cell function (HOMA2-%β), HOMA2 of insulin sensitivity (HOMA2-%S), and fasting insulin levels at baseline and 2) cumulative incident T2D at the end of 12-year follow-up were examined using generalized linear and Cox proportional hazards models, respectively. In total, 8,009 participants were included having median age of 52 years, and vegetable intake of 132 g/day. Higher intake of total vegetable, green leafy, yellow/orange/red, and moderate intakes of cruciferous vegetables was associated with lower PLG. Additionally, higher green leafy vegetable intake was associated with lower HOMA2-%β and serum insulin. Conversely, higher potato fries/chips intakes were associated with higher FPG, HOMA2-%β, serum insulin, and lower HOMA2-%S. Participants with moderate cruciferous vegetables intake had a 25% lower risk of T2D at the end of 12 years follow-up. A higher intake of vegetables, particularly green leafy vegetables, may improve while consuming potato fries/chips, but not potatoes prepared in a healthy way, may worsen glucose tolerance and insulin sensitivity. Our findings suggest a nuanced relationship between vegetable subgroups and their impact on glucose tolerance.

Modeling the impact of sea level rise on endangered deer habitat

Numerous unique flora and fauna inhabit the Lower Florida Keys, including the endangered Florida Key deer, found nowhere else. In this vulnerable habitat of flat islands with low elevation, accelerated sea level rise poses a threat. Predicting the impact of sea level rise on vegetation and wildlife is crucial. This study used 5 Intergovernmental Panel on Climate Change (IPCC) sea level rise scenarios to assess their effects on No Name Key, Florida. The goal was to estimate changes in the Florida Key deer population relative to sea level rise using a lidar-derived elevation data and a vegetation map. The method used 2 cases to model the sea level rise impact. In Case 1, total non-submerged area at current sea level was determined. Using 5 IPCC scenarios, a new total non-submerged land area was estimated, and deer numbers were predicted for each scenario. In Case 2, upward migration of coastal vegetation combined with the coastal squeeze process was modeled. A distinct elevation range for each vegetation type at the current sea level was determined. Vegetation ranges were redistributed based on respective elevation ranges in the sea level rise scenarios. Areas for each vegetation type were recalculated, and Key deer numbers were estimated for each sea level rise scenario. Results under the worst emission scenario showed the following: (1) for case 1, the land area was reduced to 30 % of the current land area, corresponding to having about 27 deer, and (2) for case 2, the land area was reduced to 70 % of the current land area, having about 54 deer on No Name Key. The results indicated reduced non-submerged land area and less upland vegetation, particularly hardwoods/hammocks, by the year 2100. As less land area is available, a decline in Key deer population is expected as sea levels rise. Since Key deer favor upland vegetation, habitat affected by sea level rise will likely support a smaller deer population. The findings emphasize the need for precise, timely predictions of sea level rise impacts and long-term conservation strategies. Specifically designed measures are required to protect and maintain endangered wildlife, such as the Florida Key deer, residing on these vulnerable islands.

Phytosociological Studies of the Flora of Dhanamanjuri University Campus in Imphal West District (Manipur), India

Aims: To study the life forms and biological spectrum of the vegetation of Dhanamanjuri University Campus, Manipur to determine its phytoclimate and species diversity. Study Design: The vegetation of the whole university campus was studied and the site selection was made randomly. Place and Duration of Study: Dhanamanjuri University Campus is located at the intersection of 24.82ºN Latitude and 93.94ºE Longitude. The study was carried out from March to September, 2023. Methodology: Life forms were determined in the study area after detailed floristic studies. Vegetation classification on a physiognomic basis as per Raunkiaer’s system as modified by Ellenberg and Mueller-Dombois. Frequency, density, abundance and basal area were calculated for quantitative analysis. Both Shannon- Weiner Index and Simpson index were calculated for diversity studies. The degree of association between two randomly selected species was studied with a simple index of association IASM. Results: The biological spectrum of Dhanamanjuri University Campus consists of 183 plant species belonging to 163 genera distributed over 74 families. Due to predominance of Phanerophytes (54.1%) and Therophytes (22.4 %) over the other life-forms, the study site was assigned to the “Phanero-Therophytic” Phytoclimate. The values of the Shannon- Weiner Index and Simpson Index were found to be 1.5202 and 3.101 respectively. For the degree of association between two randomly selected species χ2 value was calculated to be 0.101 inferring that the two species are not associated with each other, rather they are independently distributed in the site. Conclusion: The current study has described the vegetation of the Dhanamanjuri University Campus, as per Raunkiaer’s terminology as “Phanero-Therophytic” phytoclimate. The study also shed light on various phytosociological attributes of plants growing on the campus, thus shedding more light on the diversity and distribution patterns of the plants growing there.

Modeling polycyclic aromatic hydrocarbons (PAHs) concentrations from wildfires in California

In recent years, wildfires in California have increased in frequency and intensity due to climate change and prolonged drought. The air pollutants released by wildfires cause significant health consequences, among which polycyclic aromatic hydrocarbons (PAHs) are particularly toxic. Estimating PAH emissions from wildfires is challenging due to variability in vegetation types. In this study, we estimate PAH emission rates across California at a high resolution, based on laboratory-measured PAH emission rates from 22 different vegetation types and detailed vegetation mapping. By combining these estimates with biomass burning data from the NCAR Fire Inventory, the Community Multiscale Air Quality Modeling System simulates PAH concentrations for the 2017 fire season. The modeling results compare favorably to measurements from three PAH monitoring sites in California. The peak PAH emissions from wildfire events are up to be 80 times higher in the gas phase and 32 times higher in the particle phase compared to a case without fire emissions. The population-weighted PAH concentrations from the fire case (0.053 µg/m3) are 47 % higher compared to a non-fire case (0.036 µg/m3) in the particle phase and 11 % higher in the gas phase (9.82 ppt compared to 8.83 ppt) during the study period. While highly depended on the meteorological condition, the simulated spatial distribution indicates that gas-phase PAHs are less likely to travel long distances from the fire source and are prone to aging into the particle phase during transport. Consequently, populations are more likely to be exposed to particle-phase PAHs during wildfire events. This finding has important implications for understanding the health impacts of wildfire-induced PAH concentrations, as particle-phase PAHs may have different toxicological effects compared to gas-phase PAHs.

Study on Ecological Water Demand Pressure of Forest and Grass Vegetation Construction in Northwest Loess Plateau Based on Fitting Verification

In this paper, the minimum ecological water requirement of forest and grass vegetation in different types and regions and small basins in Pingliang City was analyzed and evaluated by using the quota of water consumption for ecological construction. The actual evapotranspiration water consumption of different types of vegetation was used as the quota to calculate the appropriate ecological water demand of vegetation, and the actual evapotranspiration water consumption of vegetation was used as the quota to calculate the appropriate ecological water consumption of vegetation in this region. At the same time, in order to make the calculation result more accurate, the water consumption per unit area after the actual evapotranspiration of different regions and different types of vegetation is used as the calculation quota. In addition, according to the principles of similar vegetation types, similar site conditions and similar climate environment, the research results of He Wentao et al., Institute of Geographical Sciences and Natural Resources Research, Chinese Academy of Sciences, on the ecological water requirement of forest in the whole Jinghe River basin (He Wentao et al. Determination and calculation of ecological water requirement of forest vegetation, Journal of Soil and Water Conservation, 2004, 18(6)) were selected and compared with this study. This study verifies the reliability of the calculation results of evapotranspiration water consumption of vegetation in this area. It should be noted that He Wentao et al. also evaluated the ecological water requirement of vegetation in the whole Jinghe River basin by calculating the evapotranspiration water consumption of vegetation, and analyzed the vegetation ecological water requirement deficit in 2020 by comparing the calculated minimum ecological water requirement of vegetation in the region, so as to reflect the ecological water demand pressure faced by vegetation construction in the region. It provides a basic basis for coordinating the relationship between vegetation construction and water resources in this region.

Study on Response of Evapotranspiration Consumption of Forest and Grass Vegetation to Natural Precipitation in Northwest Loess Plateau

In this paper, the evapotranspiration balance of forest and grass vegetation in the Loess Plateau of Northwest China in different regions was analyzed using 6 indexes in 3 categoriess, namely, evapotranspiration ratio (Ea/Q, Ep/Q), evapotranspiration difference (Q-EA, Q-EP), and actual (potential) water supply ratio (1-Ea/Q, 1-Ep/Q). It is used to objectively reflect the suitability of different types of vegetation in different periods of growth based on precipitation. In another words this suitability reflects the support capacity of natural rainfall to vegetation consumed water through evapotranspiration under the specific climate environment of the Loess Plateau. The results show that: (1) The actual evapotranspiration water consumption of all types of vegetation in this region increased significantly in the first three months of the growth period from April to June, resulting in a relatively high moisture dryness index of vegetation with an average k value of 0.44. The main reason was that natural precipitation was less at this stage, and the gradually rising temperature strengthened the transpiration of most vegetation. The forest was the most stressed. At the end of May and the beginning of June, with the increase of natural precipitation, the average k value of all types of vegetation began to decline. From July to September, due to the flood season in this region, the precipitation increased sharply, and the moisture dryness index was in the lowest range of the whole growth period, and the average k value varied between 0.26 and 0.30 with the lowest value was 0.26 at the end of August and the beginning of September. (2) It is obvious that the water stress of forest is higher than that of shrub and grassland. It is fully indicated that the difference of transpiration caused by the difference of vegetation types leads to the difference of actual evapotranspiration water consumption of different vegetation types.

Quantifying soil erosion and soil organic carbon conservation services in indian forests: A RUSLE-SDR and GIS-based assessment

Indian forests, having sixteen types of vegetation, provide various ecosystem services. Forests reduce water erosion of soil, reduce floods and conserve low river flow during dry seasons. Present study estimated annual sedimentation, texture, soil organic carbon control service of forests of India using the Revised Universal Soil Loss Equation (RUSLE) and Sediment Delivery Ratio (SDR) approach through GIS technique along with identifying important drivers responsible for erosion in forests. The soil erosion control service was based on five factors viz., rainfall erosivity, soil erodibility, slope, crop management, conservation practice factor and SDR across the various forest dominated river basins. Geo-detector modelling was performed to evaluate environmental drivers responsible for soil erosion. Valuation of soil control service of the India’s forests was estimated based on damage and replacement cost method. Annual soil loss rate was maximum in Tropical Thorn Forest and in Ganga River basin. Maximum sediment control and SOC conservation against the soil erosion control service by India’ forests were due to Tropical Dry Deciduous Forest with a total annual sedimentation control and SOC conservation of 33,056,560 tonnes and 3,31,115.06 tonnes, respectively. The conservative estimate of the economic value of soil conservation service by the forests of India was US$ 535.6 M with an average of 4.40 US$ ha−1 and a maximum share of value for Tropical Dry Deciduous Forest i.e. 294.18 million US$ and average maximum value for Littoral and Swamp Forest (28.91 US$ ha−1). The soil erosion in Tropical and Sub-tropical Forest was influenced by the interactive effects between NDVI and Bulk Density. In contrast, soil erosion in the temperate and alpine area was influenced by anthropogenic activity in combination with climatic factors. Present study accounts the role of India’s forests for the soil conservation service and may provide inputs to implement forest and reservoir management strategies besides providing information for Integrated Watershed management and Catchment Treatment Plans.

Study on the Application of Water Resource Management Based on GF-7 Stereo Mapping Satellite

Abstract. GF-7 satellite was successfully launched on 3 Nov 2019. The two-line stereo camera can effectively obtain 20 km-width panchromatic stereo images with resolution better than 0.8m and 3.2m-resolution multispectral images. Through the composite mapping mode of stereo camera and laser altimeter, the satellite realizes 1:10,000-scale stereo mapping. This article selected the Qiafuqihai Reservoir and its upstream of the Yili River Basin as the study area. Hydrological landforms and vegetation coverage were monitored and three-dimensional dynamic simulation software was developed to verify the potential application of GF-7 stereo mapping satellite data in supporting drainage basin water resource allocation and management in future scenarios. 3 meters DSM derived from GF-7 surveying and mapping satellite finely portrayed the characteristics of hydroponic landforms of small watersheds. The upstream of Qiafuqihai was divided into eleven small watersheds. The water density was 8.5 times more than which was produced from STRM 90m. The elevation of the water-level fluctuation zone of the Qiafuqihai Reservoir ranged from 970 to 998 meters with the water area changed from 28.3 to 57.6 square kilometres. The terrain in the northwest and northeast was flat, with the main vegetation types being natural grasslands (64.9%) and arid lands (5.03%). The three-dimensional dynamic visualization software was developed and demonstrated hydrology information, vegetation coverage information and dynamic changes in the landform of the basin in three-dimensional environment. GF-7, the stereo surveying and mapping satellite, could be perfectly able to support the application of water resources deployment and management in the future.

Exploring the spectral variation hypothesis for α- and β-diversity: a comparison of open vegetation and forests

Airborne hyperspectral imaging holds great promise for estimating plant diversity and composition, given its unprecedented combination of aerial coverage, spatial resolution, and spectral detail. Recently, there has been renewed attention toward the spectral variation hypothesis (SVH), which predicts that higher spectral variation is correlated with greater plant diversity. While several studies have highlighted methodological challenges involved with the SVH, there is little consensus about when it yields strong predictions of taxonomic, functional, and phylogenetic diversity. In part, this may be because prior studies have not explicitly considered how underlying environmental gradients drive changes in spectral and species composition. In this study, we tested the SVH separately in open vegetation (i.e. grasses and shrubs) and in forests at five sites across Canada. Generalized additive models revealed that spectral diversity was a better predictor of functional α-diversity than of taxonomic or phylogenetic α-diversity in both vegetation types. Mantel tests and Procrustes analyses revealed weak to moderate associations between spectral and plant β-diversity and composition in open vegetation, and moderate associations in forests. The better fit in forests appeared to be influenced by the presence of an elevational gradient and associated species turnover (from deciduous to coniferous trees); we observed weaker relationships when examining only a subset of this gradient. We suggest that the high variability in the strength of associations between plant and spectral diversity reported to date might be affected by the presence of environmental gradients. Finally, we found that different wavelength bands contributed to spectral α-diversity in open vegetation vs. forests, suggesting different spectral features are important for different vegetation types. In conclusion, spectral diversity is a potentially powerful tool for biodiversity assessment, but it requires a context-specific approach.

Remote sensing of vegetation and soil moisture content in Atlantic humid mountains with Sentinel-1 and 2 satellite sensor data

The satellite monitoring of vegetation moisture content (VMC) and soil moisture content (SMC) in Southern European Atlantic mountains remains poorly understood but is a fundamental tool to better manage landscape moisture dynamics under climate change. In the Atlantic humid mountains of Portugal, we investigated an empirical model incorporating satellite (Sentinel-1 radar, S1; Sentinel-2 optical, S2) and ancillary predictors (topography and vegetation cover type) to monitor VMC (%) and SMC (%). Predictors derived from the S1 (VV, HH and VV/HH) and S2 (NDVI and NDMI) are compared to field measurements of VMC (n = 48) and SMC (n = 48) obtained during the early, mid and end of summer. Linear regression modelling was applied to uncover the feasibility of a landscape model for VMC and SMC, the role of vegetation type models (i.e. native forest, grasslands and shrubland) to enhance predictive capacity and the seasonal variation in the relationships between satellite predictors and VMC and SMC. Results revealed a significant but weak relationship between VMC and predictors at landscape level (R2 = 0.30, RMSEcv = 69.9 %) with S2_NDMI and vegetation cover type being the only significant predictors. The relationship improves in vegetation type models for grasslands (R2 = 0.35, RMSEcv = 95.0 % with S2_NDVI) and shrublands conditions (R2 = 0.52, RMSEcv = 45.3 %). A model incorporating S2_NDVI and S1_VV explained 52 % of the variation in VMC in shrublands. The relationship between SMC and satellite predictors at the landscape level was also weak, with only the S2_NDMI and vegetation cover type exhibiting a significant relationship (R2 = 0.28, RMSEcv = 18.9 %). Vegetation type models found significant associations with SMC only in shrublands (R2 = 0.31, RMSEcv = 9.03 %) based on the S2_NDMI and S1_VV/VH ratio. The seasonal analysis revealed however that predictors associated to VMC and SMC may vary over the summer. The relationships with VMC were stronger in the early summer (R2 = 0.31, RMSEcv = 90.1 %; based on S2_NDMI) and mid (R2 = 0.37, RMSEcv = 70.8 %; based on S2_NDVI), butnon-significant in the end of summer. Similar pattern was found for SMC, where the link with predictors decreases from the early summer (R2 = 0.33, RMSEcv = 16.0 %; based on S1_VH) and mid summer (R2 = 0.30, RMSEcv = 17.8 %; based on S2_NDMI) to the end of summer (non-significant). Overall, the hypothesis of a universal landscape model for VMC and SMC was not fully supported. Vegetation type models showed promise, particularly for VMC in shrubland conditions. Sentinel optical and radar data were the most significant predictors in all models, despite the inclusion of ancillary predictors. S2_NDVI, S2_NDMI, S1_VV and S1_VV/VH ratio were the most relevant predictors for VMC and, to a lesser extent, SMC. Future research should quantify misregistration effects using plot vs. moving window values for the satellite predictors, consider meteorological control factors, and enhance sampling to overcome a main limitation of our study, small sample size.

Seventy-five years of vegetation change after fire in Tasmanian alpine heathland

Context Alpine ecosystems are threatened by warming and an associated increase in fire frequency. There is a gap in our knowledge of succession in Tasmanian alpine heath more than 50 years after fire. The literature suggests that the alpine successional progression usually involves decreasing rates of change, decreasing differences among fire ages, ongoing transitions among shrub species, ongoing transitions from some lifeforms/species to others, and that warming results in increases in species richness. Aims We test for these tendencies up to 75 years from fire in alpine vegetation on kunanyi/Mount Wellington, Tasmania, Australia. Methods We documented the changes in vegetation structure and composition between 1998 and 2022 in plots on either side of an alpine fire boundary in the alpine heathland and used earlier data and observations to extend the record of change after fire to 75 years. We put these changes in the context of the only area of alpine vegetation that was not burnt in 1947 or later. Key results The area last burnt in 1947 exhibited declines in all lifeform covers between 1998 and 2022. All lifeforms except tall shrubs and mat shrubs declined in cover in the area last burnt in 1962. By 2022, shrub cover in the 1962-burnt area had not attained equivalence with the area last burnt in 1947. Herbs had the most dramatic decline in both fire-age classes. There were few shrub seedlings in 2022. All but six taxa, three being exotic, were observed in both the plots and previous broader surveys. Increases in species richness caused by the upward migration of lower-elevation species were not observed. The long-unburnt patch lacked the major dominant of the 1947-burnt plots, namely Orites acicularis, and was dominated by a gymnosperm absent from most of the mountain. Conclusions Succession follows the initial floristic composition model. The differences in trajectories from the 1947 and 1962 fires could possibly be due to desiccation or abrasion damage from increasing wind speeds and temperatures. There are strong indications of further potential change in the absence of fire. Implications The slow rate of recovery and its on-going nature emphasise the importance of keeping fire out of this vegetation type.

The spatial variation and drivers of soil δ13C in an alpine-gorge region on the eastern Qinghai-Tibetan Plateau

Soil stable carbon isotope (soil δ13C) can reflect soil carbon metabolic processes and record environmental and vegetation change information, so mapping the spatial distribution of soil δ13C (isoscapes of soil δ13C) can help us better understand the spatial variability of ecosystem carbon cycles. However, efficient approaches for obtaining the isoscapes of soil δ13C remain challenging, especially in mountainous areas with complex terrain. A total of 150 soil samples were collected and their soil δ13C was measured to investigate the spatial variation of soil δ13C in an alpine-gorge region on the eastern Qinghai-Tibetan Plateau which is characterized by complex terrain. Four prediction methods included ordinary kriging interpolation, multiple linear regression, random forest regression, and geographically weighted regression (GWR) were selected and compared to find the best prediction model for mapping the isoscapes of soil δ13C. The pathways of vegetation, topography, soil, and spatial factors influencing the spatial variability of soil δ13C were explored using variance partitioning analysis and structural equation model. The soil δ13C was significantly different among vegetation types, and ranged from −27.155‰ to −9.647‰. The spatial heterogeneity of soil δ13C showed moderate variation, and was dominated by spatial structural factors. The GWR model had higher prediction accuracy in the modeling soil δ13C in comparison to other models. Soil carbon to nitrogen ratio and normalized difference vegetation index were the main factors determining the spatial variability of soil δ13C, and other topographic and soil factors indirectly regulated the spatial distribution of soil δ13C by influencing these two factors. Our results provided a useful tool (GWR model) for mapping the isoscapes of soil δ13C and explored the factors controlling the spatial variability of soil δ13C in the alpine-gorge region on the eastern Qinghai-Tibetan Plateau, which are important for an in-depth understanding of soil carbon cycling in mountain ecosystems.

Functional trait patterns: investigating variation-covariation relationships and the importance of intraspecific variability along distinct vegetation types

Functional trait patterns: investigating variation-covariation relationships and the importance of intraspecific variability along distinct vegetation types

Asymmetric warming has different impacts on vegetation growth across various vegetation types on the Tibetan Plateau

ABSTRACT Global warming could affect vegetation growth, while land surface temperature has exhibited an asymmetric warming pattern over the past 50 years. The Tibetan Plateau, known as “the roof of the world,” experiences the surface warming almost twice as high as the global average. However, previous research has largely overlooked the impacts of this asymmetrical warming on vegetation growth and the temporal changes in these impacts. In this study, we assess the effects of asymmetric warming on vegetation growth at regional and different vegetation types by using partial correlation analysis, and reveal the temporal changes of impacts strength using time moving window. The results showed that there had been a significant greening trend (1.01 × 10−3 yr−1, p < 0.01) in the Normalized Difference Vegetation Index (NDVI) during the growing season, as well as significant warming trends in both maximum temperatures (Tmax, 0.0354°C yr−1, p < 0.01) and minimum temperatures (Tmin, 0.0333°C yr−1, p < 0.01) during 2000–2021. Under the background of asymmetric warming, the grassland showed stronger impacts of Tmin than Tmax on NDVI, while the opposite effects were observed for forests. Over time, the response of NDVI to Tmax and Tmin has intensified. This study highlights importance of asymmetric warming in the projection of climate change on vegetation in similarly vulnerable ecosystems worldwide.

Relicts of Threatened Biodiversity: Similarities and Differences among the 7230 EU Habitat Plant Communities on Montane Plateaus of Central Apennines, Italy

The habitats protected by the European Union (EU) include most peat vegetation, such as mires, swamp mires, fens, and peat bogs—all belonging to the classes Oxycocco–Sphagnetea and Scheuchzerio–Caricetea fuscae and carrying the Habitat Codes 71xx and 72xx. These types of vegetation are typical of cold and cool temperate climates, while they become rarer in Southern Europe where Mediterranean influences prevail, representing relic fragments of the past glacial climatic conditions there. Because of their limited extension and the increasing warmth and drought due to climate change, they are seriously threatened. Even if many studies were performed, their richness and distribution across Europe are still not well–understood, and only a few examples are known from the Central and Southern Apennines to date. In order to provide the syntaxonomical classification of the alkaline fens referable to the EU Habitat 7230 found on the mountain plateaus of the Central Apennines, we analyzed their species structure and flora composition, together with their chorological and ecological characteristics. We also evaluated their conservation status, pressures, and threats. The alkaline fens of the Central Apennines are found to be poorer in diagnostic species when compared to similar communities of Central and Northern Europe. However, they are rich in the species of the surrounding meadows and pastures. Among them, the new subassociation Caricetum davallianae caricetosum hostianae is described.

Spatial analysis of fire sevetiry and its relationship with landscape configuration in savanna areas of Sempre Vivas National Park, Brazil

Fire is a natural disturbance in the Cerrado (Brazilian savanna) but its effects on the landscape are capable of altering its pattern of severity and frequency. Because of that, some areas of the Biome can be in dangerous in the National Park of Sempre Vivas, in Minas Gerais State. Within this context, we spatially analyzed fires in areas of Cerrado during the years 2003 and 2017 according to severity, frequency and the influence of the spatial configuration of the area. We used pre- and post-fire Landsat satellite images to calculate the dNBR index to analyze fire severity per year and used fire metrics to analyze the relationship between fire severity and the spatial configuration of the landscape. Fire-scar severity was considered low, probably due to the density and structure of the typical Cerrado vegetation and the change in annual precipitation. Thus, fires in the Cerrado can be intense and spread quickly if no proper control is implemented.

Prediction of Potential Suitable Distribution Areas for an Endangered Salamander in China.

Climate change has been considered to pose critical threats for wildlife. During the past decade, species distribution models were widely used to assess the effects of climate change on the distribution of species' suitable habitats. Among all the vertebrates, amphibians are most vulnerable to climate change. This is especially true for salamanders, which possess some specific traits such as cutaneous respiration and low vagility. The Wushan salamander (Liua shihi) is a threatened and protected salamander in China, with its wild population decreasing continuously. The main objective of this study was to predict the distribution of suitable habitat for L. shihi using the ENMeval parameter-optimized MaxEnt model under current and future climate conditions. Our results showed that precipitation, cloud density, vegetation type, and ultraviolet radiation were the main environmental factors affecting the distribution of L. shihi. Currently, the suitable habitats for L. shihi are mainly concentrated in the Daba Mountains, including northeastern Chongqing and western Hubei Provinces. Under the future climate conditions, the area of suitable habitats increased, which mainly occurred in central Guizhou Province. This study provided important information for the conservation of L. shihi. Future studies can incorporate more species distribution models to better understand the effects of climate change on the distribution of L. shihi.

Species richness and ecological connectivity of the mammal communities in urban and peri-urban areas at Mexico City

AbstractUrban expansion has emerged as a pervasive driver of biodiversity loss in Mexican cities due to shifts in landscape composition and configuration. Hence, the preservation of forest cover, green spaces and isolated trees assume a critical role in conserving the biodiversity within urban areas. We compared mammal assemblages across 520 sites in Mexico City examining the impact of local vegetation and site characteristics (e.g., patch size, isolation distance) on diversity patterns. Then, we used a generalized linear model to evaluate the relationship between mammal assemblages (including both alpha and beta diversities) and the level of structural and functional connectivity across the landscape. We collected 5,063 records of 38 species from the sampled sites. Mammalian richness ranged from 1 to 9 spp./site, and the mean of taxonomic and functional (Functional Distance [MFD]) alpha diversities were 1.9 ± 1.3 spp./site and 0.41 ± 0.60 MFD/site, respectively. The average size of habitat fragments was 0.41 hectares, and the percent forest cover per site ranged from 0.5 to 100%. Both species and functional alpha diversities were different among the land-use and vegetation types (including protected vs. non-protected areas). There was a clear distinction (β value &gt; 0.40) in species composition across the landscape, which was positively related to geographical distance and negatively related to connectivity between sites. We identified four main patches especially important to connectivity across the city and argue that conserving them is critical for restoring key components of biodiversity and ecosystem services in urban and peri-urban areas of Mexico City.

Enhancing salt marshes monitoring: Estimating biomass with drone-derived habitat-specific models

Salt marshes play a vital role in biodiversity conservation, coastal protection, and carbon sequestration. Estimating aboveground biomass (AGB) is crucial for quantifying the carbon sequestration capacity of the system. However, traditional fieldwork methods are time-consuming, demanding, and detrimental to marsh ecosystems. In this study, we propose utilizing low-altitude remote sensing techniques to collect high-resolution LiDAR and multispectral (MS) data for biomass assessment. With these datasets, we characterized salt marsh vegetation habitats through the analysis of vegetation indices (VIs) variability. LiDAR high-resolution topographic information aids in evaluating habitat distribution. Moreover, the Anthocyanin Reflectance Index 2 (ARI2), combined with the Digital Surface Model, allows for the identification and separation of the two habitats with distinct dominant species (Sarcocornia spp. and Sporobolus maritimus). The analysis of the annual cycle of VIs reveals the presence of seasonality. However, the VIs for the two vegetation classes exhibit dissimilar seasonal changes, indicating distinct growth mechanisms for each. Biomass models are created for each season in the annual cycle. Habitat-specific models exhibit higher precision (up to 99%) than models that treat species uniformly. Depending on whether the marsh is considered as a whole or separated into dominant habitats, differences in biomass estimation trends are observed. This implies that the two dominant species exhibit varying behaviours throughout the year, contributing to diverse biomass production. The study reveals a seasonal pattern in the total AGB, with the highest biomass value in summer and the lowest peak in spring, with annual variation accounting for only 9% of total output. The reduced AGB value in spring may be due to increased soil salinity and stress. The use of LiDAR and MS data from an unmanned aerial vehicle (UAV) is crucial for accurately distinguishing primary marsh habitats and creating detailed biomass models, with unprecedented accuracy. This method is user-friendly, repeatable, and cost-effective, enabling the study of salt marshes, evolutionary trends, and climate change response requiring less fieldwork.

Variation and plasticity in life-history traits and fitness of wild Arabidopsis thaliana populations are not related to their genotypic and ecological diversity

BackgroundDespite its implications for population dynamics and evolution, the relationship between genetic and phenotypic variation in wild populations remains unclear. Here, we estimated variation and plasticity in life-history traits and fitness of the annual plant Arabidopsis thaliana in two common garden experiments that differed in environmental conditions. We used up to 306 maternal inbred lines from six Iberian populations characterized by low and high genotypic (based on whole-genome sequences) and ecological (vegetation type) diversity.ResultsLow and high genotypic and ecological diversity was found in edge and core Iberian environments, respectively. Given that selection is expected to be stronger in edge environments and that ecological diversity may enhance both phenotypic variation and plasticity, we expected genotypic diversity to be positively associated with phenotypic variation and plasticity. However, maternal lines, irrespective of the genotypic and ecological diversity of their population of origin, exhibited a substantial amount of phenotypic variation and plasticity for all traits. Furthermore, all populations harbored maternal lines with canalization (robustness) or sensitivity in response to harsher environmental conditions in one of the two experiments.ConclusionsOverall, we conclude that the environmental attributes of each population probably determine their genotypic diversity, but all populations maintain substantial phenotypic variation and plasticity for all traits, which represents an asset to endure in changing environments.